The mounting of tail rotors of helicopters presents problems somewhat more difficult of solution than mounting main helicopter rotors because of the smaller size involved, preventing utilization of some of the measures that are readily adaptable to larger main rotor mountings.
Indicative that problems are involved in providing suitable bearings for use in tail rotors of helicopters is a paper entitled, "Elastomeric Bearing Application To Helicopter Tail Rotor Designs" by C. H. Feagan, published in 1968 by the Southwest Region of the American Helicopter Society and also published in the October, 1968 issue of the American Helicopter Society Journal. Various uses of elastomeric radial bearings and elastomeric thrust bearings were discussed. Also indicated were the use of bonded elastomeric radial bearings and molded elastomeric radial bearings for mounting a tail rotor on its teetering axis.
It has been found that significant improvements can be achieved by utilizating bearings hereinafter described to mount a rotor on its flapping axis.